(ITS#3942) back-ldap does not return the "matched" field on search as appropriate

Full_Name: Pierangelo Masarati
Version: HEAD/re23
OS: Linux
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (131.175.154.56)
Submitted by: ando
..essentially because the pointer to the string is stored in the bv_val member
of a berval, but the length is left to zero. Then the berval is tested for
non-empty...
A fix is coming.